1. Field of the Invention
The present invention relates to a filter for the separation of solids and liquids from muds and specifically those from industrial processing.
Before continuing it is noted that in the present description and the claims the term muds means generally fluids of varying chemical composition and different physical properties which contain dispersed solid particles.
2. Description of the Background Art
The use of filters in industrial plants in general is now very widespread for reasons of environment protection, originating in the ever stricter standards applied and for more rigourously economic reasons. In many cases, indeed, environmental standards prescribe an obligation to dispose of a considerable number of substances from industrial processes in especially assigned centres. These substances are mostly present in fluids such as sewage and various type of muds and suspensions from chemical processes but it is not rare to find liquids used for cooling of machines. To limit the volume of fluid to be treated and reduce the quantity of material to be hauled in the disposal centres it is important to provide adequate separation of the solid component from the liquid in the fluid.
In addition, confirming the usefulness of the above mentioned filters, those industrial processes in whose waste fluids there are substances which it is advantageous to recover due to their high economic value must be taken into consideration. Of course, even in these cases the effectiveness of the solid and liquid separation operation is quite important.
From Italian patent no. 1.184.501 a filtering container is known for the separation of solids and liquids in which are provided two mutually moving overlying parts of which the first or upper defines a chamber for reception of a bag full of muds to be filtered while the second or lower is designed to penetrate through the base of the first substantially in the manner of a piston. As a result of the movement of the lower part the bag of mud is deformed and compressed so that the liquid contained therein can flow out through the filtering fabric of which the bag is made.
Another example of a mud filter substantially similar to the one described above is known from another Italian patent no. 1.188.227. Also in this second example there is a chamber for housing a bag of muds to be filtered and in which the volume is swept by a compressed air driven piston.
Basically, for both the above cases, operation of the filters calls for the relative movement of two coupled parts in which the filter structure is divided. Even though the procedures according to which said movement takes place are different, in one case gravity is used while in the other compressed air is used, the technical solutions proposed are unsatisfactory, especially as concerns the size and construction complexity of the filters obtained.
Indeed, there being provided two mutually moving parts, the travel of the latter necessitates adequate mechanical means, especially running guides, drive means and everything else, which make the filters very cumbersome and complicated, especially-considering their yield and efficiency. This shortcoming must indeed be considered in the light of the industrial end purpose of these filters, which must treat high quantities of fluid while ensuring steady production over time associated with continuous operational reliability. It should be noted also that the parts making up the filter operate in contact with liquids of varying chemical composition in which there are also dispersed solid particles. Thus their mutual movements take place in particularly severe environmental conditions and may easily lead to failure.